My hum disappears fully when I attached a wire between the grounding posts on the SUT and my phono preamp. Not sure if you said if tried that above.
Hum with Ypsilon MC26L SUT that goes away with touching
I need help solving the hum problem.
Ikeda Kai cartridge -> Ypsilon MC26L SUT -> Ypsilon VPS 100 -> Cary SLP 05 -> Cary CAD 211FE monoblocks -> KEF Blade.
ICs between MC26L and VPS100 Stage 3 concepts RCA
ICs between VPS100 and Cary SLP 05 Stage 3 concepts XLR
Cary SLP 05 and Cary monoblocks Shunyata RCA
Cary monoblocks to KEF Blade Shunyata speaker cables.
Connected ground from tonearm phonocable to SUT grounding post ->I hear 60 hz hum
Connected ground from tonearm phonocable to SUT grounding post + connected SUT grounding post to VPS 100 ground ->I hear 60 hz hum (slightly decreased)
Connected ground from tonearm phonocable directly to VPS 100 ground (I read in the forums to try this) -> I hear 60 hz hum
If I touch the body of SUT (metal) with one hand and touch the metal frame of the rack that sits directly on the floor, the hum disappears in all the above situations.
I used two shorting RCA plugs into input loading of SUT with tonearm cable connected to input-> No Hum
I used two shorting RCA plugs into input of SUT without tonearm cable-> No Hum
I used two shorting RCA plugs into output loading of SUT -> No Hum
Any help in solving this hum problem is greatly appreciated.
Thanks
Kanchi
Ikeda Kai cartridge -> Ypsilon MC26L SUT -> Ypsilon VPS 100 -> Cary SLP 05 -> Cary CAD 211FE monoblocks -> KEF Blade.
ICs between MC26L and VPS100 Stage 3 concepts RCA
ICs between VPS100 and Cary SLP 05 Stage 3 concepts XLR
Cary SLP 05 and Cary monoblocks Shunyata RCA
Cary monoblocks to KEF Blade Shunyata speaker cables.
Connected ground from tonearm phonocable to SUT grounding post ->I hear 60 hz hum
Connected ground from tonearm phonocable to SUT grounding post + connected SUT grounding post to VPS 100 ground ->I hear 60 hz hum (slightly decreased)
Connected ground from tonearm phonocable directly to VPS 100 ground (I read in the forums to try this) -> I hear 60 hz hum
If I touch the body of SUT (metal) with one hand and touch the metal frame of the rack that sits directly on the floor, the hum disappears in all the above situations.
I used two shorting RCA plugs into input loading of SUT with tonearm cable connected to input-> No Hum
I used two shorting RCA plugs into input of SUT without tonearm cable-> No Hum
I used two shorting RCA plugs into output loading of SUT -> No Hum
Any help in solving this hum problem is greatly appreciated.
Thanks
Kanchi
27 responses Add your response
If hum does not go away when everything is grounded to everything, start removing ground wires, one by one. But it does seem your SUT wants to be grounded to something, and you are already grounding the tonearm to the SUT and the SUT to the phono stage, correct? Finally, you have several pieces of gear in your phono chain. Are all the items plugged into the same AC source (same wall socket)? If not, they should be. Small AC voltage differences in grounding of one wall socket vs another, even in the same room off the same circuit breaker, can cause hum. |
Might want to clean the contact points on the ground at the TT. Remove it clean it reinstall and tighten it. Clean all surfaces on the grounds. Dirty contacts don't have to look green to have a bad or lose contact. Loosen and retighten stuff. Plug and unplug to clean the contacts. Kinda of a crude way, but quick. Alligator clips and wire, for testing. Jumper leads. Keep them in the tool bag, ay? Want to get real picky. use a DMM, and see if there is a voltage difference, between the Turntable and Preamp, at the chassis GROUND. If there is a difference, there is a good chance they lost contact, at the ground wire, either end. Check for continuity, in the power off position, between chassis, CLEAN or repair the wire as needed. Happy hunting Regards |
@kanchi647 Are you suggesting to connect another wire between ground post from VPS 100 to Cary SLP 05? I do not see a grounding post on SLP 05. I'm saying ground your SUT to something. In my case I have a grounding post on my SUT and also one on my phono preamp. It's unlistenable without this wire in place. |
@lewm all my components are connected to Shunya V-ray which has 8 outlets. Yes, I am already grounding the tonearm to the SUT and the SUT to the phono stage. Is there a way to connect the ground from Phono stage to pre-amp and amps? Just touch the body of the amps? How do the wires stay in place? @stringreen I used a junk wire and connected the SUT and made contact with the metal rack. Hum did not go away. It only goes away when I place my palm on the metal rack and have good contact. How do I make good contact using the wire to the metal frame? I will get some wire from lowes tomorrow. @oldhvymec the contacts look clean. How do I clean the contacts? Is there a solution you recommend? Thanks for all the help |
Clean means shiny metal, to shiny metal. An eraser is good on copper or brass. A small wire brush (tooth brush size). I use carbon steel, brass bristle, and nylon. Wipe the surfaces, with isopropyl, contact cleaner, or a little WD 40 on a Q Tip. It will remove all the moisture and put a light protective coat. Screws with securements (nuts, wing nuts, the like) just work them back and forth...and a light lube, Wipe off the excess. LOL never found a squeak I couldn’t stop... If you’re worried about scratches. Tape off the work area with painters tape before you start, ay.. BTW, Nice Preamp.. Really one of my favorites..Lot of craftsmanship there.. That has an umbilical cord. right? might want to unplug that and plug it in a few times.. clean the contacts... The UC.. Just to make sure.. You’ll get it.. Regards |
I feel your pain and had the near same problem.Turn the power off at the breaker box then run a separate wire from the turntable ground to the ground post in the wall socket then you should have a true uninterrupted ground also you may want to make sure all your interconnect wires are properly attached to the end connectors. I had an rca that the connection was broken on which caused a hum like you described The ground directly to the outlet ground should work. Good luck Willy-T |
Dear @kanchi647 : two things, first and to avoid ground loops we need to have a dedicated true ground connection ( this means a 2-3m. cooper solid tube underwround and touching a combination of salt and other ingredients and then atached to it a heavy cooper wire/cable. ) that will be connected directly to the phonolinepreamp and all electronicswill be be grounded to this item and your TT/SUT/TOnearm must has a ground wire to the phonolinepreamp. The second thing you need to do it’s to take out your cartridge and clean perfectly its output pin connectors and when you reconnected to the tonearm wires stay totally sure that the tonearm wire connectors makes a tigth connection into the cartridge output pin connectors. Yes you have to clean any single input/output connector in your system and that at each connection it makes tigth connection. Now your Kai cartridge has a low output level of 0.19mv along very low internal resistance of 2.5 ohms. For me that cartridge will be better served with an active high gain phonolinepreamps than a SUT but this is only additional of what I writed here and obviously does not helps to your today issue. Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
Update: the hum disappeared after I replaced the Stage 3 concepts analord interconnect from SUT to Ypsilon VPS100 with Ypsilon interconnect. i also made my own IC using helix design from http://www.image99.net/blog/files/category-002a002a-the-helix-image-interconnect.html and the Hum disappeared. can anyone explain why the hum disappeared with just changing the IC? Thanks |
Also, many audiophile single-ended, RCA-terminated ICs are built such that the shield is only grounded to one end. The manufacturer will typically mark the cable for polarity. In such cases, it could make a difference which end is connected to the input vs the output side, in terms of hum and noise. I take it that BOTH the Ypsilon IC and your home-made IC cured the hum problem. Did you connect the ground conductor and the shield to BOTH ends of the home-made cable or just one? |
@lewm my home made IC doesn’t have a sheild or ground conductor. Neither does the IC made by Ypsilon. The Stage 3 concepts IC has a ground conductor and I tried multiple configurations which had hum- including connecting only one side, both sides, none, directly connecting the ground of stage 3 to the TT phonocable and VPS100 and bypass SUT. |
@kanchi647 Unfortunately like many expensive audio cables, the Stage 3 Concepts phono cables are rich on fancy materials, multiple shields, and fancy sounding jargon. The reality is that there are no electrical specifications on their website for their phono cables. Given that they claim 4 layer shielding for their phono cables, and use star quad ribbon configuration for signal it could well be that it is the inherent electrical parameters ( LCR ) of the interconnect that are inducing hum between the transformer and phono. For example, cables that are capacitive can be prone to hum/rf, particularly in this situation where the signal coming out of the transformer is high voltage, very very low current, meaning the signal is more sensitive to the cable. |
@kanchi647 Yes, but star quad will have much higher capacitance than a single twisted pair. Plus they use a ribbon wire - it would be interesting to measure the capacitance - I suspect it is not as low as you might think. Otherwise it could be the shield - you could try connecting the shield at one end only to true ground - not the earth posts on the phono/SUT. When you are touching the SUT you are grounding it. |
I hope you already solved your problem. I have a similar setup, vps100 many ypslion sut's. Short version stage 3 ic's are the reason of the hum. If you insist on using stage 3, which are great cables, (my all ic's are satge3 except the one sut>phone pre), you should use their phono spesific cables. Try different ic's for sut to phone stage. You will see the difference. I ended up with ansuz ic's, zero hum. I tried transparent cables at that that time and hum were still there. I believe nordost cables would be a good choice too. |
